“Claim language employing terms of degree has long been found definite where it provided enough certainty to one of skill in the art when read in the context of the invention.” Interval Licensing LLC v. AOL, Inc., 766 F.3d 1364, 1370 (Fed. Cir. 2014). The Specification provides examples of the claimed geometric shapes and configurations, e.g., the “substantially circular cross-sectional shape” of the second segment of the keel (see Spec. ¶ 64, Fig. 5C), such that a skilled artisan would understand the metes and bounds of the term “substantially” as used in these claims.